The quality and efficaciousness and in some instances safety of certain pharmaceutical products and other non-durable products deteriorate when frozen or exposed to temperatures below a predetermined limit. Certain vaccines, if frozen, suffer a loss of potency which cannot be restored, thereby diminishing the effectiveness of the vaccine and increasing the risk of adverse events, such as sterile abscesses, following immunization. Vaccines damaged by freezing include Diphtheria Toxoid, Hepatitis A, Hepatitis B, Influenza, Liquid Hib Conjugate, Pertussis, Pneumococcal Conjugate, Poliovirus (inactivated), Tetanus Toxoid, Typhoid (inactivated) and combinations containing these vaccines. Other pharmaceutical products, including insulin and certain morphine suspensions for injection, are also damaged by freezing. The freezing point for a given vaccine or other pharmaceutical product is dependent on a number of factors including temperature, rate of temperature change, duration of exposure, supercooling effects and vibration.
A number of indicators have become available that undergo a colour change when exposed to freezing temperatures. FREEZEmarker®, produced by the Temptime Corporation (USA), and Freeze Watch™, produced by the 3M Corporation (USA), are label-type devices designed to be affixed to or placed within the packaging for products that can be damaged when exposed to freezing temperatures and inform the user, by means of a colour change, if a freeze event has occurred. Freeze-tag produced by Berlinger and Company AG (DE) and FreezeAlert produced by Sensitech Inc (USA) are battery operated electronic temperature monitoring devices that inform the user, by means of an electronic display, if a freeze event has occurred. Freeze indicators of these types are designed to activate, subject to a tolerance of accuracy, at a predetermined temperature in line with the assumed freezing point of the vaccine or other pharmaceutical product with which they are to be packaged. However, they do not take into account factors such as rate of temperature change, supercooling effects and vibration that may affect the freezing point of the vaccine or other pharmaceutical product. They also suffer the disadvantage that the user is relied upon to correctly interpret and act in accordance with the indication provided.
To ensure product quality and efficacy and to safeguard the health and safety of consumers, a need therefore exists to prevent the use of certain nondurable products if frozen or exposed to temperatures below a predetermined limit.
W02006/077087 discloses a device for dispensing ice cream. The device comprises a container having an aperture through which material in the container can be dispensed, a closure for the aperture that is biased by a spring into a closed position, and a connecting temperature-sensitive element that is rigid below a predetermined temperature, whereby the closure can be opened, and non-rigid above that temperature, so that the element does not connect the container and the closure and the latter cannot be opened. This effect is designed to be reversible.
WO02/056820 discloses a closure cap apparatus for a medicament container. The device comprises a container having an aperture through which material in the container can be dispensed and a closure for the aperture which utilises the change in shape of a shape-memory-alloy from a second shape to a first shape to prevent access to the contents of the container should the container be exposed to a temperature above a predetermined limit. The effect is designed to be irreversible but does not prevent access to the contents of a container which deteriorate when frozen or exposed to temperatures below a predetermined limit.